Examples of known portable toilets to which the present invention relates are disclosed in U.S. Pat. No. 3,570,018, patented Mar. 16, 1971 in the names of Sargent et al.; U.S. Pat. No. 3,949,430, patented Apr. 13, 1976 in the names of Miller et al.; and U.S. Pat. No. 4,145,773, patented Mar. 27, 1979 in the names of Sargent et al. Reference is also made to pending U.S. application, Ser. No. 957,799, filed Oct. 6, 1978 in the names of Frank T. Sargent et al.
Portable toilet of this character have holding tanks on which are removably mounted upper units which contain among other items, the toilet bowl, a flush water storage tank and flush apparatus for flushing waste material from the bowl into the holding tank. It is the conventional practice in each of these toilets to provide a valve assembly either on the outside or within the holding tank for opening and closing the tank inlet port that is in communication with the outlet port from the toilet bowl. The tank contains a discharge spout with a closure cap, the spout normally being located in one of the side walls of the holding tank where it is visable and below the liquid line of the tank when the latter is full. The improved holding tank disclosed in the aforementioned application Ser. No. 957,799 has its discharged spout located in its top wall with the opening of the spout at a level above that of the valve assembly. This construction and arrangement enables the user of the portable toilet to remove the closure cap and to introduce selected chemical preparations into the holding tank while the liquid contents are in the tank without the danger of spilling the contents. It also significantly reduces the sealing problems that are involved for assuring that leakage does not occur at the closure cap while the portable toilet is in use. Still further, it conceals the closure cap and spout when the portable toilet is in its assembled position to provide a more attractive portable toilet.